JP2007309617A - Gas cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To utilize the water obtained by decomposition of natural gas hydrate (NGH) in a gas cooling system. <P>SOLUTION: This gas cooling system 10 comprises a NGH tank 11 storing NGH, a NGH decomposing device 12 for decomposing NGH supplied from the NGH tank 11 into a fuel gas and water, an absorption type refrigerating machine 13 producing cooling water, and an air conditioner 14 producing cold air by using the cooling water produced by the absorption refrigerating machine 13. The fuel gas produced by the NGH decomposing device 12 is supplied to the absorption-type refrigerating machine 13, and used as a fuel for cooling. The cold water produced by the absorption-type refrigerating machine 13 is supplied to the air conditioner 14 to be used as the cooling water of the air conditioner 14. Further the water secondarily produced by the NGH decomposing device 12 is also supplied to the air conditioner 14 (or its peripheral device) to be subsidiarily used in producing cold air by the air conditioner 14. The cold air produced by the air conditioner 14 is used in cooling the inside of a building 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas cooling system, and more particularly, to a gas cooling system using natural gas hydrate (NGH) as fuel.

In recent years, natural gas hydrate (NGH) has attracted attention as a fuel in consideration of the global environment (see Non-Patent Document 1). NGH is a clathrate hydrate in which natural gas molecules (guests) mainly composed of methane, ethane, propane, etc. are incorporated into a cluster of water molecules, and is about 170 under an atmospheric pressure environment of minus 20 ° C. Double the gas can be stored. As gas energy, liquefied natural gas (LNG) is well known, but since LNG is manufactured and stored at an extremely low temperature of minus 162 ° C, NGH is used in the entire system of manufacturing, transportation, storage, and gasification. There are many advantages over LNG. NGH is attracting attention as clean energy because it emits less carbon dioxide and air pollutants than gasoline.
Mitsui Engineering & Shipbuilding Co., Ltd., “Natural Gas Hydrate (NGH)-Mitsui Engineering & Shipbuilding”, [online], [Search May 10, 2006], Internet <URL: http://www.mes.co.jp/mes_technology /ngh.html> JP 2001-336804 A JP 2005-214519 A

  By the way, in large buildings such as condominiums, hotels, commercial buildings, hospitals, factories, and warehouses, an absorption gas cooling system using the heat of vaporization of water is adopted as one of the cooling facilities. However, the cooling efficiency of the absorption gas cooling system is not sufficient, and further improvement is desired.

  NGH can also be used as a fuel for such a gas cooling system, but a fuel such as methane gas is obtained by the decomposition of NGH, while a large amount of water is produced as a secondary. Since the generation rate of water is about 80% by volume ratio with respect to NGH, a considerably large amount of water is generated. However, in the past, the only way to drain was.

  Accordingly, an object of the present invention is to provide a gas cooling system utilizing water obtained by NGH decomposition.

  The object of the present invention is to provide an NGH tank in which NGH is stored, an NGH decomposition apparatus that decomposes NGH supplied from the NGH tank to generate fuel gas and water, an air conditioner that generates cold air, and an air conditioner An absorption refrigerator that generates first cooling water to be used for cooling, fuel gas generated by the NGH decomposition apparatus is used for driving the absorption refrigerator, and water generated by the NGH decomposition apparatus is supplied by an air conditioner. This is achieved by a gas cooling system characterized in that it is used for generating cold air.

  The gas cooling system of the present invention preferably further includes a heat exchanger that cools a heat medium involved in the air conditioner, and supplies water generated by the NGH decomposition apparatus to the heat exchanger. Here, the heat medium may be the first cooling water discharged from the air conditioner, or the first cooling water supplied to the air conditioner, which is cold air generated by the air conditioner. It may be air taken into an air conditioner. In either case, a gas cooling system with a high cooling capacity can be provided.

  In the present invention, the absorption refrigerator is an evaporator that cools the first cooling water discharged from the air conditioner using the heat of vaporization of water, and the water vaporized in the evaporator is absorbed by the lithium bromide solution. An absorber, a regenerator that evaporates water absorbed in the lithium bromide solution by heating the lithium bromide solution, a condenser that liquefies the water and regenerates water, and an absorber and a condenser It is preferable that the 2nd cooling water produced | generated by the cooling tower is supplied with respect to an absorber and a condenser including the cooling tower which produces | generates the 2nd cooling water for cooling. Here, the 2nd cooling water produced | generated by the cooling tower may be supplied in series with respect to an absorber and a condenser, and may be supplied in parallel.

  According to the present invention, by mounting an NGH decomposition apparatus in a gas cooling system, fuel gas obtained from NGH is used as fuel for an absorption refrigeration machine, and water obtained from NGH is used for generating cold air by an air conditioner, It is possible to reduce the load on the air conditioner and increase the cold air output, and to provide a gas cooling system with a high cooling capacity.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram schematically showing a basic configuration of a gas cooling system according to a first embodiment of the present invention.

  As shown in FIG. 1, this gas cooling system 10 generates an NGH tank 11 in which NGH is stored, an NGH decomposition device 12 that decomposes NGH supplied from the NGH tank 11 into fuel gas and water, and cooling water. And an air conditioner 14 that generates cold air using the cooling water (first cooling water) generated by the absorption refrigerator 13. The fuel gas generated by the NGH decomposition device 12 is supplied to the absorption refrigerator 13 and used as a cooling fuel. The absorption refrigerator 13 generates cold water, which is supplied to the air conditioner 14 and used as cooling water for the air conditioner 14. In addition, the water generated as a secondary by the NGH decomposition apparatus 12 is also supplied to the air conditioner 14 (or its peripheral equipment), and is supplementarily used for generating cold air by the air conditioner 14. The cold air generated by the air conditioner 14 is used for cooling in the building 15.

  FIG. 2 is a schematic diagram showing the configuration of the NGH decomposition apparatus 12.

  As shown in FIG. 2, the NGH decomposition apparatus 12 includes an NGH decomposition tank 21 for decomposing pellet-shaped NGH (NGH pellets) supplied from the NGH tank 11 and heat exchange for generating hot water for NGH decomposition. A heat pump 22, a pump 23 for supplying a part of the water discharged from the NGH decomposition tank 21 to the heat exchanger 22, and hot water from the heat exchanger 22 above the NGH pellet 20 in the NGH decomposition tank 21. And a nozzle 24 for spraying. A net 25 is provided inside the NGH decomposition tank 21, and the NGH pellet 20 and the water 26 in the decomposition tank 21 are separated vertically by this net 25. The fuel gas generated in the NGH decomposition tank 21 is discharged from a gas discharge port 21 a provided above the NGH decomposition tank 21, and the water 26 generated in the NGH decomposition tank 21 is provided below the NGH decomposition tank 21. It is discharged from the drain 21b. The water obtained at this time is cold water, and the water temperature is lower than room temperature. In addition, you may provide the water temperature regulator which adjusts the temperature of the water obtained with the NGH decomposition | disassembly tank 21. FIG. Moreover, you may produce | generate the hot water for NGH decomposition | disassembly using the water supplied from the outside, without utilizing a part of decomposition water as the hot water for NGH decomposition | disassembly.

  FIG. 3 is a schematic diagram showing in detail the detailed configuration of the gas cooling system 10 (particularly the absorption refrigerator 13).

  As shown in FIG. 3, the absorption refrigerator 13 used in the gas cooling system 10 is a single-effect absorption refrigerator, and an evaporator 31 that vaporizes water and an absorption that absorbs the vaporized water in a lithium bromide solution. A regenerator 33 for evaporating water absorbed in the lithium bromide solution by heating the lithium bromide solution, a condenser 34 for liquefying water vapor to regenerate water, an absorber 32 and condensation And a cooling tower 35 that generates cooling water (second cooling water) for cooling the vessel 34.

  The first cooling water discharged from the air conditioner 14 is sent to the evaporator 31 through the drainage line 38a. This cooling drainage is cooled by the heat of vaporization of the evaporator 31, and is air-conditioned through the water supply line 38b. It is sent to the machine 14 and used again as cooling water (first cooling water) of the air conditioner 14. The pressure in the evaporator 31 is 6 to 7 mmHg, and the water supplied from the condenser 34 is heated by the heat of the cooling wastewater and vaporized at about 5 ° C. On the other hand, the heat of the cooling wastewater is reduced by being taken away as the heat of vaporization, whereby the cooling wastewater is cooled to about 7 ° C., for example.

  The water vaporized in the evaporator 31 is absorbed by the lithium bromide solution (concentrated solution) in the absorber 32. For this reason, the density | concentration of the lithium bromide solution supplied from the regenerator 33 becomes low. This lithium bromide solution (diluted solution) is supplied to the regenerator 33 by the pump 36a, and is heated by the regenerator 33, whereby the moisture of the lithium bromide solution evaporates and the lithium bromide solution is concentrated. This lithium bromide solution is supplied to the absorber 32 again. On the other hand, the water evaporated by heating the regenerator 33 is supplied to the condenser 34, cooled by the cooling water in the condenser 34, and returned to the original water. This water is supplied again to the evaporator 31.

  The cooling water generated by the cooling tower 35 is supplied to the absorber 32 through the line 39 and the pump 36 b, and then supplied to the condenser 34 and then sent back to the cooling tower 35. That is, the cooling water circulates through the cooling tower 35, the absorber 32, and the condenser 34, and is supplied in series to the absorber 32 and the condenser 34.

  The fuel gas generated by the NGH decomposition apparatus 12 is supplied to the gas burner 33a of the regenerator 33, used as fuel for evaporating the water content of the lithium bromide solution, and also supplied to the gas equipment in the building 15. . Moreover, the cold water produced | generated by the NGH decomposition | disassembly apparatus 12 is supplied to the heat exchanger 37 installed in the middle of the drainage line 38a between the air conditioner 14 and the absorption refrigerator 13 (evaporator 31). And used as cooling water for lowering the temperature of the cooling waste water of the air conditioner 14. With this heat exchanger, the temperature of the cooling drainage discharged from the air conditioner 14 can be lowered to about 12 ° C., for example.

  As described above, according to the present embodiment, not only the fuel gas obtained from the NGH decomposition apparatus 12 is used as fuel for the gas cooling system, but also the water obtained from the NGH decomposition apparatus 12 is used as the cooling drainage of the air conditioner 14. Since it uses for cooling, the cold water which is a by-product of NGH can be used effectively. Thereby, while being able to reduce the load of the absorption refrigerator 13, the output of the absorption refrigerator 13 can be increased. In other words, the same cooling capacity can be obtained with less fuel, and a larger cooling capacity can be obtained with the same fuel.

  FIG. 4 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the second embodiment of the present invention.

  As shown in FIG. 4, the gas cooling system 20 is characterized in that a line connected to the drain of the cooling tower 35 is branched in the middle, one of the branches is connected to the absorber 32, and the other is a condenser. It is in the point connected to 34. That is, the cooling water generated by the cooling tower 35 is supplied in parallel to the absorber 32 and the condenser 34 through the line and the pump 36b. Since other configurations are the same as those of the first embodiment, description thereof is omitted here.

  In the first embodiment described above, since the cooling water is supplied to the condenser after passing through the absorber 32, the cooling water whose temperature has risen slightly is supplied to the condenser 34. According to the embodiment, the cooling water without such a temperature rise can be supplied also to the condenser 34. In addition, it cannot be overemphasized that the effect similar to 1st Embodiment can be acquired.

  FIG. 5 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the third embodiment of the present invention.

  As shown in FIG. 5, the gas cooling system 30 is characterized in that a heat exchanger 37 is provided in the middle of a water supply line from the absorption refrigerator 13 (evaporator 31) to the air conditioner 14. The cold water generated as a secondary by the NGH decomposition apparatus 12 is used as cooling water that further reduces the temperature of the cooling water of the air conditioner. Since other configurations are the same as those of the first embodiment, description thereof is omitted here. According to this embodiment, the temperature of the cooling water supplied from the absorption refrigerator can be sufficiently lowered.

  FIG. 6 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the fourth embodiment of the present invention.

  As shown in FIG. 6, the gas cooling system 40 is characterized in that the cooling water generated by the cooling tower 35 is supplied in parallel to the absorber 32 and the condenser 34 through the line and the pump 36b. is there. Moreover, the heat exchanger 37 is provided in the middle of the water supply line from the absorption refrigerator 13 (evaporator 31) to the air conditioner 14. That is, this embodiment is a combination of the second and third embodiments. Since other configurations are the same as those of the first embodiment, description thereof is omitted here.

  According to this embodiment, the cooling water without such a temperature rise can be supplied also to the condenser 34. Moreover, according to this embodiment, since the temperature of the cooling water supplied from the absorption refrigeration machine 13 can be made sufficiently low, the cooling capacity of the air conditioner can be further improved.

  FIG. 7 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the fifth embodiment of the present invention.

  As shown in FIG. 7, the gas cooling system 50 is characterized in that a heat exchanger 37 is provided at the air outlet of the air conditioner 14. Since other configurations are the same as those of the first embodiment, description thereof is omitted here. According to the present embodiment, since the cold air generated by the air conditioner 14 is further cooled and supplied by the heat exchanger 37, the temperature of the cold air can be sufficiently lowered.

  FIG. 8 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to a sixth embodiment of the present invention.

  As shown in FIG. 8, the gas cooling system 60 is characterized in that a heat exchanger 37 is provided at the air outlet of the air conditioner 14. Moreover, the heat exchanger 37 is provided in the middle of the water supply line from the absorption refrigerator 13 (evaporator 31) to the air conditioner 14. That is, this embodiment is a combination of the second and fifth embodiments. Since other configurations are the same as those of the first embodiment, description thereof is omitted here. According to the present embodiment, since the cold air generated by the air conditioner 14 is further cooled and supplied by the heat exchanger 37, the temperature of the cold air can be sufficiently lowered.

  FIG. 9 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to a seventh embodiment of the present invention.

  As shown in FIG. 9, the gas cooling system 70 is characterized in that a heat exchanger 37 is provided at the air inlet of the air conditioner 14. Since other configurations are the same as those of the first embodiment, description thereof is omitted here. According to this embodiment, since the air taken into the air conditioner 14 is cooled in advance by the heat exchanger 37, the temperature of the cold air can be sufficiently lowered.

  FIG. 10 is a schematic diagram showing a configuration of a gas cooling system (particularly the absorption chiller 13) according to the eighth embodiment of the present invention.

  As shown in FIG. 10, the gas cooling system 80 is characterized in that a heat exchanger 37 is provided at the air inlet of the air conditioner 14. Moreover, the heat exchanger 37 is provided in the middle of the water supply line from the absorption refrigerator 13 (evaporator 31) to the air conditioner 14. That is, this embodiment is a combination of the second and seventh embodiments. Since other configurations are the same as those of the first embodiment, description thereof is omitted here. According to this embodiment, since the air taken into the air conditioner 14 is cooled in advance by the heat exchanger 37, the temperature of the cold air can be sufficiently lowered.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above-described embodiment, a single effect absorption refrigerator is taken as an example, but the present invention can also be applied to a double effect absorption refrigerator. Moreover, although lithium bromide has been described as an example of the absorbent, the present invention is not limited to this, and any other absorbent may be used.

FIG. 1 is a schematic diagram schematically showing a basic configuration of a gas cooling system according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of the NGH decomposition apparatus 12. FIG. 3 is a schematic diagram showing the configuration of the absorption refrigerator 13 in detail. FIG. 4 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the second embodiment of the present invention. FIG. 5 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the third embodiment of the present invention. FIG. 6 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the fourth embodiment of the present invention. FIG. 7 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to the fifth embodiment of the present invention. FIG. 8 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to a sixth embodiment of the present invention. FIG. 9 is a schematic diagram showing a configuration of a gas cooling system (particularly, absorption chiller 13) according to a seventh embodiment of the present invention. FIG. 10 is a schematic diagram showing a configuration of a gas cooling system (particularly the absorption chiller 13) according to the eighth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas cooling system 11 Tank 12 NGH decomposition | disassembly apparatus 13 Absorption-type refrigerator 14 Air conditioner 15 Building 20 Gas cooling system 20 NGH pellet 21a Gas discharge port 21b Drain port 21 NGH decomposition tank 22 Heat exchanger 23 Pump 24 Nozzle 25 Net 26 Water (decomposed water)
30 Gas cooling system 31 Evaporator 32 Absorber 33 Regenerator 33a Gas burner 34 Condenser 35 Cooling tower 36a Pump 36b Pump 37 Heat exchanger 38a Drain line 38b Water supply line 39 Line 39a Line 39b Line 40 Gas cooling system 50 Gas cooling system 60 Gas cooling system 70 Gas cooling system 80 Gas cooling system

Claims (9)

An NGH tank in which NGH is stored;
An NGH decomposition apparatus that decomposes NGH supplied from the NGH tank to generate fuel gas and water;
An air conditioner that generates cold air;
The absorption chiller for generating the first cooling water used for cooling the air conditioner,
The fuel gas generated by the NGH decomposition apparatus is used for driving the absorption refrigerator,
A gas cooling system, wherein the water generated by the NGH decomposition apparatus is used for generating the cold air by the air conditioner. A heat exchanger for cooling the heat medium involved in the air conditioner;
The gas cooling system according to claim 1, wherein the water generated by the NGH decomposition apparatus is supplied to the heat exchanger.   The gas cooling system according to claim 2, wherein the heat medium is the first cooling water discharged from the air conditioner.   The gas cooling system according to claim 2 or 3, wherein the heat medium is the first cooling water supplied to the air conditioner.   The gas cooling system according to any one of claims 2 to 4, wherein the heat medium is the cold air generated by the air conditioner.   The gas cooling system according to any one of claims 2 to 5, wherein the heat medium is air taken into the air conditioner. The absorption refrigerator is
An evaporator for cooling the first cooling water discharged from the air conditioner using heat of vaporization of water;
An absorber that absorbs water vaporized in the evaporator into a lithium bromide solution;
A regenerator for evaporating moisture absorbed in the lithium bromide solution by heating the lithium bromide solution;
A condenser for liquefying the water and regenerating the water;
A cooling tower for generating a second cooling water for cooling the absorber and the condenser,
The gas cooling system according to any one of claims 1 to 6, wherein the second cooling water generated by the cooling tower is supplied to the absorber and the condenser.   The gas cooling system according to claim 7, wherein the second cooling water generated by the cooling tower is supplied in series to the absorber and the condenser. The gas cooling system according to claim 7, wherein the second cooling water generated by the cooling tower is supplied in parallel to the absorber and the condenser.

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